Decision support at the point of prescribing to increase formulary adherence.

Purpose: Study results demonstrating the effectiveness of order-entry clinical decision support (CDS) alerts as a tool for enforcing therapeutic interchange are presented.

Methods: A retrospective observational study was conducted at an academic medical center to evaluate formulary nonadherence before and after implementation of a fully electronic medical record with computerized prescriber order-entry (CPOE) technology configured to display therapeutic interchange alerts immediately on entry of orders for nonformulary agents. Formulary nonadherence (defined as the proportion of pharmacist-verified nonformulary orders to total verified orders) within eight medication classes was assessed during a six-month baseline period and two consecutive six-month periods after implementation.

Results: In the 12 months after implementation of the therapeutic interchange alerts, the overall rate of formulary nonadherence decreased by 65%, from 3.5% at baseline to 1.2% during the second 6-month postintervention period (p < 0.001). The total number of verified nonformulary orders decreased from 300 at baseline to 102 during the second postintervention period. The largest decreases in formulary nonadherence were observed in the intranasal steroid drug class (the rate of nonadherent orders declined by a total of 12 percentage points) and the nonbarbiturate sedatives and hypnotics class (a 5-point decline), with significant 6- and 12-month declines also documented in four of the remaining six drug classes.

Conclusion: The incorporation of hard-stop CDS alerts into the CPOE system improved the overall rate of prescriber adherence to institutional therapeutic interchange protocols.